Domino Effect Definition

noun

A cumulative effect produced when one event sets off a chain of similar events.

The domino effect of increasing the speed limit in one of several contiguous states.

American Heritage

(politics, historical) The theory that, if South Vietnam fell to Communism, it would be followed by Cambodia, Laos, and additional South Asian countries.

Wiktionary

Other Word Forms of Domino Effect

Noun

Singular:

domino effect

Plural:

domino effects

Origin of Domino Effect

From the fact that a row of dominoes stood on end will fall in succession if the first one is knocked over

From American Heritage Dictionary of the English Language, 5th Edition
An allusion to a row of dominoes in which the fall of one leads to a cascade of falling pieces

From Wiktionary